Technical Field
The present invention relates to a semiconductor device and a measurement device.
Related Art
Recently, in measurement devices such as electricity meters for measuring integral power consumption, there is an increasing demand to separately measure integral power consumption by time band. Accompanying this trend, measurement devices are known that include a built-in semiconductor device equipped with an oscillator and an integrated circuit, in order to enable measurement of power and time.
As an oscillation device employed in such a measurement device, an oscillation device is known (for example, Japanese Patent Application Laid-Open (JP-A) No. 2009-213061) in which an oscillator and an IC chip that oscillates the oscillator are disposed side-by-side along the plane direction on one face of a single wiring board, with the one face of the wiring board sealed with resin.
A piezoelectric device is known (for example, JP-A No. 2008-219348) in which an IC is mounted to a wiring board, a piezoelectric transducer is stacked on the IC, and connection pads of the IC and external terminals of the piezoelectric transducer are connected together by solder balls.
Moreover, a piezoelectric oscillation device is known (for example, JP-A No. 2007-234994) in which a piezoelectric transducer is mounted to one face of a lead frame, and an integrated circuit including an oscillation circuit that drives the piezoelectric transducer is mounted to the other face of the lead frame.
The oscillation device, the piezoelectric device and the piezoelectric oscillation device of these references are devices in which an oscillator and an oscillation circuit are integrated together. However, since the oscillation device, the piezoelectric device and the piezoelectric oscillation device respectively include the two components of a microcontroller that performs timing and an oscillation device, coordination between these components is required.
Moreover, in the oscillation device of JP-A No. 2009-213061, the mounting surface area tends to become larger due to the oscillator and the IC chip being disposed side-by-side along the plane direction on the one face of the single wiring board.
In JP-A No. 2008-219348 and JP-A No. 2007-234994, the semiconductor device can be made more compact compared to cases in which an integrated circuit and an oscillator are mounted side-by-side on one face of a lead frame. However, since wiring needs to be pulled round to the back side of the lead frame in order to electrically connect the integrated circuit to the oscillator, the wiring resistance may become high.
To address this, a device might be considered in which an oscillator is disposed to one face of a lead frame, an integrated circuit, such as an LSI formed with a circuit for performing processing using a clock supplied from the oscillator, is disposed on the other face of the lead frame, and these components are integrally sealed together with a resin.
However, it is necessary to consider the influence imparted by the oscillator that is now disposed in a package on the flow of resin when performing resin sealing during manufacture of this device. Unless, there is a possibility that voids and the like arise inside the device due to failing effective discharge of air entrapped in the resin.
Further, in cases in which the oscillator has a higher height than the integrated circuit, since it is difficult to dispose the lead frame at the center of a mold in the height direction, there is a possibility that the pressure from poured resin on the lead frame becomes uneven between both faces of the lead frame. In such cases, since there is a need to match the height direction dimension of the cavity in the mold to the oscillator if attempting to dispose the lead frame at the center of the height direction of the mold, the thickness of the sealing resin of the semiconductor device increases than in cases in which the lead frame is not disposed at the center of the height direction of the mold.